Improvement in manufacture of elliptic springs



, i MANUFAUTURE 0F ELL'IPTlC-SPRIN'GS.

Patented Feb. 6,1877.

NPETERS. PHOTO-LITHOQRAPHER. WASHINGTON, 0v C.

.UNITED STATES Pnfrnufr @risica AARON FRENCH, OF PITTSBURG, PENNSYLVANIA, ASSIGNOF TO A.' FRENCH Y & CO., OF SAME PLAGE.

IMPROVEMENT in MANuFAc'ruRE cF ELLIPTIC SPRINGS.

Speciiication forming part of Letters Patent No. 186,999, dated February 6, 1877; application liled December 7, 1876.

To all whom 'it ma/y concern:

Be it known that I, AARON FRENcH, of

Pittsburg, county of Allegheny, `State of the latter; and Fig. 3 shows the product in perspective.

In the manufacture of elliptic or semi-ellip tic leaf-springs, particularly the heavier sizes, such 'as are designed for railroadcar use, a solid welded band has to be placed around the several .leaves of the spring, at each eX- Ytremity of the minor axis of the ellipse. This band has heretofore, after being cut, bent, IWelded, and slipped loosely on, been tightened onto the spring by hammering, first, two opposite faces, and then giving the half-sprin g a quarter-turn, hammering the two othc; opposite faces, (one, of course, resting onl a die `and the other being struck by a hammer,) and so on alternately until the band was thought to be properly tightened. Ihave found, however, that this mode of tightening springbands does not in allcases give a satisfactory result, since' the swaging action on two sides tends to force the two other sides away from the spring, and to that extent prevent the attainment of the desired result. I have hence invented a hydraulic press, which gripes the band on all its `four lateral faces simultaneously, and compresses the band into the spring from all sides at once, or first on two opposite sides, and then, while still held under pressure on such two sides, on its two other opposite sides, so that thereby the leaves composing each half-spring shall be firmly and securely locked as against displacement in any direction.` The dies employed in this operation are removable, so that, other dies belng substituted, the operation referred to may,

by the use of a single machine, be employed on bands and springs of all sizes.

The frame of the machine A is of any suitable form or construction with reference to the ends in view. It carries two fixed dies, a

c, by means of die-blocks a c', or in other suitable way. The faces of these dies stand at right angles to each other, so as to form two adjacent sides ot' an open-ended die-box, and 'the areas of such faces are such as to cover two adjacent faces oi' the band D.

The other two sides of the open-ended die-box consist of the movable dies d c, having a like arrangement oi' faces, and attached by dieblock d c, or in other suitable way, to the plungers b b oi' the hydraulic cylindersB B', the latter being mounted on or made as apart of the frame A, and in the proper position for the advance and back movement of the dies d e.

The water-pressure is applied and regulated by means of pipes g g g g', and the proper arrangement of cocks.

The middle section or portion of the leaves of one-half of an elliptic car-spring (the number of the leaves not being material) are represented at D, and the band referred to at D'.

The latter is cut, bent, and welded in the usual or any desired way, and, being properly heated, is slipped loosely onto the half-spring D. The dies d e being at the end of their back stroke the spring and band are placed With two faces ot' the latter against the dies a o, as shown in Fig. 2. Pressure is then applied back of the pistons which actuate the plungers b b', so that the dies d e advance against the other two faces of the band, as shown in Fig. 2, and by a continuation of the pressure compress the band so that it shall be caused to embrace the spring tightly and securely on all sides. These dies d c may for this purpose be caused to advance and act compressively both at the same time, or one may so act in advance of the other, retaining, however, its gripe until such other has also done its work. Then, by a reversal of the l pressure, both are caused to move back, the product is removed, and the operation repeated on another band. The work thus produced is vastly superior in its quality to any heretofore made, not only in the fact that the band gripes the leaves of the spring so tightly that they cannot be or become loose or liable to displacement in any direction, but also in the'act that the external "we of tl ve band is left with a smooth finish on its bearing sides,

and "with well-filled square corners, such asv cannot be secured by other known modes of manipulation. Such a spring and. band will work better in use and give better results when combined with a car-body thanany other like device yet made.

As shown in the drawing, the die-blocks which carry the dies are, by the use of adove-y tail joint, made removable, so that dies for other sizes of bands may be inserted. Other able dies simultaneously in compressing springbands, substantially as set forth.

In testimony whereof I have hereunto set Vmy hand.

AARON FRENCH.

` Witnesses:

J. J. MoOoRmoK, OLAUDIUs L. PARKER. 

